Codec is a piece of software or a computer program used to compress / decompress your media files like songs or videos. Media players like Windows Media Players use these codecs to play and create your media files. Codec stands for “Coder / Decoder.
Most of the audio / video formats use a sort of compressor to reduce the memory space utilization. When you save a song or a video, the codec will compress that file and appends a small piece of code to decompress it. Again, when you try to open it and play them; the codec decompresses the file to play it. Codecs are mainly used in streaming media, video editing and video conferencing etc. you can use any codec, but should be compatible with the media recorder, media player that is used to play the file.
Are both Codec and file formats same?
Many a times, people get confused with the codec and file formats as they have same names. But they are different! If you consider a file format as a container within which it contains files which are compressed by a particular codec. For example, consider Windows Media Audio format, which contains the data compressed by Windows Audio Video codec. In case of AVI format, it may contain files that are being compressed by many codecs like Xvid, DivX, MPEG-2 etc. and it may also contain data that is not compressed.
Commonly used Codecs:
Some of the commonly used codecs are: